Many exhaust valves today are located in mufflers. Installing an exhaust valve inside a muffler is a difficult task. Due to many moving parts and tight tolerances, existing exhaust valves are difficult and expensive to manufacture.
Many exhaust valves are butterfly valves inside a flow path which create unwanted noise. Such noise may be due to metal on metal contact and/or a failure of the plate inside the muffler to move to a desired orientation. Another problem with existing butterfly valves is failure due to component wear. Such components include bushings, shafts and springs.
Conventional exhaust valve plates are designed to close at idle or low engine speeds, and open progressively inside a flow path, such as a pipe, as the engine speed and exhaust gases increase. Consequently, the angle of the valve plate relative to the tube in which the valve plate is located changes depending upon the speed of the engine. For example, when the engine is idling, the valve plate is positioned generally perpendicular to the exhaust flow, and when the engine operates at full open throttle, the valve plate is positioned generally parallel the exhaust flow. Engine noise may be reduced due to sound waves being deflected off the valve plate when the engine is at idle because of the position of the valve plate, generally perpendicular to the exhaust flow. On the other hand, engine noise may undesirably increase due to sound waves not being deflected off the valve plate when the engine is at higher speeds because of the position of the valve plate, more parallel to the exhaust flow in the flow path.
Therefore, it is one objective of the present invention to maintain the position of the valve plate of an exhaust valve in a position generally perpendicular to the exhaust flow to decrease unwanted engine noise at all engine speeds.
It is another objective of the present exhaust valve assembly to increase the efficiency of an exhaust system in which the exhaust valve assembly is used, such as increasing fuel efficiency and/or emissions quality.
It is another objective of the present exhaust valve assembly, when used downstream of a catalytic converter, to increase the efficiency of the catalytic converter.
It is another objective of the present exhaust valve assembly to provide a hinge-less, lever-less valve with few moving parts less expensive to manufacture than existing exhaust valves and more reliable.